The Stovebolt Site Forums The Shop Area Engine Shop Vapor Lock? Or why is my truck dying?

Spent 2 hours in a parade yesterday, 95 degree heat, very slow. On the highway home, truck ran great then started to sputter, jerk and die....as it slowed, I roll-started it, it would run for 5 minutes then repeat the process. Full tank of premium. Restarts from a stop impossible, just crank and crank, although it should have been fast enough to turn over. I hate to turn it over to a mechanic with no more idea that than this, what would you all do? Fuel filter? Carb? Battery? I'm sure dozens of you have had similar problems, what's the fix? THANKS!!!! (btw, got nothing but thumbs up in the parade!)

Fred: These old stovebolts are very dependable engines, provided all systems are functioning and in reasonal parameters of adjustment.

Since you stated in your post that you idled and/or slow speed operation for 2 hours before these problems arose, it would seem your ride is in fairly good running condition. Here are some things to check-

If engine is NOT overheated:

1. condition of plugs-regap or replace
2. point gap and adjustment-check/adjust/replace
3. fuel filter-replace, there cheap.
4. Float valve blocked,plugged, or float off adjustment. Open carb check set level. Check seat and needle
5. fuel delivery from pump, possible blockage or cracked pump diaphram-disconnect pump outlet, use coffee can and crank engine, check delivery
6. scale or crud blockage at fuel tank. Disconnect line at pump inlet. Backflush with air to tank. Make sure you remove tank fill cap.

If engine IS overheated, check:

1. heat riser valve stuck or spring broken
2. plugs/points
3. air cleaner restricted/dirty
4. exhaust restricted
5. water pump operation (belt adjusted)

More people will jump in on this soon!
Good Luck and think Chevy!

sounds like plugged fuel line, from finally agitating enuff junk loose in the tank to pump it - if ya got an inline fuel filter, might be plugged - if ya don't have one then the carb might be plugged - next time it happens, have tools w/ ya to pop top off carb and see if the bowls empty - otherwise try this one!! - if it's vapor lock, letting it sit w/ hood up for 10 min will clear it, and the pump will be able to work again - skip the mechanic until ya know what's wrong!!

Bill

Don't forget the ole coil and coil wire,mine use to run like a top. then stop when ever, it would always restart but just about drove me crazy, I replaced the coil and I have had no problem since, I found out that alot of these old trucks are just trial and error even with all of the good advise from the bolt, sounds like a fuel problem but sometimes if you are getting fuel it is in the electrical part, at least we do not have to deal with the new electronic stuff...good luck..Fred

Fred - just remembered about the fuel pump problem I had on my 235 - actuator arm worn so bad that it was barely pumping - once going it would do ok at slow speeds on the level, but too much load and it couldn't keep up and the carb would go dry . . .

Bill

Fred,
If you're not sure whether it's a fuel or electrical problem, remove air cleaner, dribble an ounce of gas into the carb. Get in and try to start it. If it's a gas starvation problem, she should fire up and run for a second or two. If no joy, try it one more time before looking for an electrical problem.
I remember years ago a similar problem after I had the corner garage mechanic give my 55 Chev a "tune up". He didn't tighten the screw holding the new condenser in the distributor. Drove me crazy for weeks before we found it.
Frets

FYI, it was as simple as a clogged fuel filter and fuel line. Sorry, next time I'll try the easy stuff before I post. Thanks for your suggestions if it ever dies again!!!!

glad to hear that you found the problem and that it was an inexpensive one to fix....Fred

Glad it is fixed
Do ot be afraid to post, it may help someone else who is having a similar problem get things figured out with all the replies and suggestions given.

Please keep posting your problems. That keeps all of the experts (which I am not) on their toes instead of rocking back on their heels.

I had a 54 and had a problem with the coil. It was a bit oily on the out side as well as everything under the hood. After replacing most of the electical parts I was left with the coil. After that the only problem I had was the bird bath carb. The truck ran until the coil heated up then quit and would not start till the coil cooled down.